PULSED-FIELD IONIZATION ELECTRON SPECTROSCOPY OF LANTHANIDE (Gd, Lu) BENZENE COMPLEXES M. ROUDJANE, S. KUMARI and D.-S. YANG University of Kentucky Lexington, KY 40506

OVERVIEW MOTIVATION AND OBJECTIVES EXPERIMENTAL SETUP THEORETICAL CALCULATIONS RESULTS AND DISCUTION CONCLUSIONS

MOTIVATIONS :  Previous Studies in our lab: Sc, Y, La-C 6 H 6 [1] ;  Chemistry of organometallics f-elements complexes [2] ;  Experimental data are not available in UV range;  Only ab initio calculations of metal-ring bonding [3].  Structure and electronic ground states for neutral and ion  Ionization energy  Vibrational frequencies of the complex [1] B. R. Sohnlein, S. Li, and D.-S. Yang, J. Chem. Phys. 123, (2005). [2]Aline M. Nonat, Susan J. Quinn, and Thorfinnur Gunnlaugsson. Inorg. Chem. 2009, 48, [3] Gongyi Hong, Friedemann Schautz, and Michael Dolg. J. Am. Chem. Soc. 1999, 121, OBJECTIVES :

EXPERIMENTAL SETUP Source chamber ZEKE Spectrometer Turbo pump Diffusion pump HV Gate Valve

EXPERIMENTAL SETUP Cluster beam Source and Pulsed Valve Ligand chamber Carrier Gas Mixture Extraction Can MCP  -Metal Shielding Turbo pump Diffusion pump HV Gate Valve TOF SHG 532 nm

PIE of Gd-C 6 H 6 80 psi He AIE ≈ (100)

ZEKE SPECTRUM for Gd-C 6 H psi He Wavenumber (cm -1 ) [4] B.R. Sohnlein, S. Li, and D. –S. Yang, J. Chem. Phys. 123, /7 (2005). Sc-C 6 H 6

COMPUTATIONAL  Density functional theory calculations to optimize geometries and frequencies B3LYP, B3P86, MP G(d,p) {C and H} ECP28 MWB, ECP60 MWB,SEG,SDD{Gd, Lu} ECPnX Y n = number of core electrons X = S/M: single/multi electron fit Y = HF/WB/DF: non/quasi/fully relativistic  Multidimensional Franck-Condon factor calculations  Spectral simulation at finite temperature using a Boltzmann distribution

ELECTRONIC STRUCTURE OF Gd-C 6 H 6 E(cm -1 ) 0 11 A 1 (0) 9 A 1 (3805) 8 A 1 (38819)* 10 A 1 (39988) Relative energies of different molecular states of Gd-Benzene using MP2 and SDD basis set Exp.IE(40830) ion neutral Gd [Xe] 4f 7 5d6s eV (NIST) *: calculated using 28 MWB basis set ΔS=±1

ZEKE SIMULATIONS SPECTRA C6v Using MP2 method and the SDD basis set 10 A 1 11 A Wavenumber (cm -1 )

C 6v ZEKE SIMULATIONS SPECTRA 10 A 1 9 A 1 Wavenumber (cm -1 )

C 6v Comparison between the two electronic transitions ZEKE SIMULATIONS SPECTRA 10 A 1 11 A 1 10 A 1 9 A 1 Wavenumber (cm -1 )

psi He n04n K14K Assignments of Gd-C 6 H 6 Spectrum Wavenumber (cm -1 )

MoleculeAIE(cm -1 )Gd-C 6 H 6 stretch (cm -1 ) Gd-C 6 H (5) /39988 ν + =298/300 ν =256/281 Comparison between experimental and theoretical (MP2+SDD) results. 10 A 1 11 A 1 OUR WORK (MP2+SDD) PREVIOUS WORK (MP2+ECP) Ground State Gd-C 6 H 6 stretch freq (cm -1 ) 11 A A Comparison with previous theoretical results [2]. [2] Gongyi Hong, Friedemann Schautz, and Michael Dolg. J. Am. Chem. Soc. 1999, 121,

ORBITAL DIAGRAM Gd Gd-C 6 H 6 (C 6v ) C 6 H 6 1a 1 2e 2 a1a1 2a 1 2e 1 1e 1 e1e1 5d 1 6s 2 Energy (eV) d xy, x 2 -y 2 d xy, yz dz2dz2 4f 7 e2e ≈ 24 4f 7 6.2

PIE of Lu- C 6 H 6 AIE ≈ (50) 80 psi He Wavenumber (cm -1 )

ZEKE SPECTRUM for Lu-C 6 H 6 He psi He Atomic line Wavenumber (cm -1 )

ELECTRONIC STRUCTURE OF Lu-C 6 H 6 E(cm -1 ) 0 4 A 1 (0) 2 A 1 (1370)* 1 A 1 (40541)* 3 A 1 (42280) Relative energies of different molecular states of Lu-Benzene using MP2 and SDD basis set Exp.IE(44447) ion neutral Lu: [Xe] 4f 14 5d 6s eV (NIST) *: calculated using 28 MWB basis set ΔS=±1

ZEKE SIMULATIONS SPECTRA Using MP2 method and the SDD basis set 180 K 10 K 80 psi He 3A1 3A1 4A1 4A Atomic line

CONCLUSIONS Future:  Improve the calculations for Lu-benzene complex,  Analysis of the recorded ZEKE spectrum of lanthanide-benzene. EXPGd-C 6 H 6 Lu-C 6 H 6 AIE (cm -1 ) Freq (cm -1 ) (5) ν + =298/ ν = (5) ν + =270/ ν =204 The MP2 method/ SDD basis set are suitable for our calculations, The ground neutral and ionic electronic states of Gd-benzene were identified to be 11 A 1 and 10 A 1 respectively, The ground neutral and ionic electronic states of Lu-benzene was identified to be 4 A 1, Calculation of the Ionization energy and Vibration frequencies of the complex Gd-benzene.

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